It enters the FPGA via HDGC (High-Density I/O Bank Global Clock) pins. These can only directly drive BUFGCE primitives, not
MMCM/PLL primitives. See Global Clock Inputs in ug572 (https://www.xilinx.com/support/documentation/user_guides/ug572-
ultrascale-clocking.pdf). It can still drive MMCM/PLL indirectly, but this will need a CLOCK_DEDICATED_ROUTE FALSE
constraint, otherwise Vivado DRC will fail.
Is available whenever the PHY is out of reset and is not specifically configured through its registers to disable this clock. By default it
is synchronous to the crystal input of the Ethernet PHY (25 MHz ()).
Add info on GTR and GTH reference clocks
The Genesys ZU provides several different methods of resetting the Zynq Ultrascale+ device, as described in the following sections.
The Zynq Ultrascale+ PS supports external power-on reset signals. The power-on reset is the master reset of the entire chip. This signal
resets every register in the device capable of being reset. The Genesys ZU drives this signal from the PG_ALL signal of the power supplies
in order to hold the system in reset until all power supplies are valid. The Genesys ZU also has a red push button, labeled POR, which can
toggle the power-on reset of the Zynq Ultrascale+.
A red push button, labeled PROG, toggles the Zynq Ultrascale+'s PS_PROG_B input. This resets the PL and causes DONE to be deasserted. The PL will remain unconfigured until it is reprogrammed by the processor or via JTAG.
The external system reset button, labeled SRST, resets the Zynq Ultrascale+ device without disturbing the debug environment. For example,
the previous break points set by the user remain valid after system reset. Due to security concerns, system reset erases all memory content
within the PS, including the On-Chip-Memory (OCM). The PL is also cleared during a system reset. System reset does not cause the boot
mode strapping pins to be re-sampled. After changing boot moode jumpers a power-on reset is needed to act on the new setting.
For more details about configuration pins see “Clock, Reset, and Configuration Pins” section in Zynq UltraScale+ Device Technical
Reference Manual (UG1085) (https://www.xilinx.com/support/documentation/user_guides/ug1085-zynq-ultrascale-trm.pdf).
A Microchip ATWINC1500 module provides 2.4GHz IEEE 802.11 b/g/n wireless network connectivity. It interfaces to the MPSoC on the
PS-side over SPI, supporting a maximum theoretical data rate of 48Mbps. The ATWINC1500 can be used in bare-metal applications with
the full IP stack included in the firmware loaded from flash. However, it is also supported in Linux in the ATWILC1000-compatible mode,
where the firmware is loaded on-the-fly upon boot and the OS () IP stack is used.
The Genesys ZU uses a TI DP83867CR PHY to implement a 10/100/1000 Ethernet port for wired connectivity. The PHY connects to
MIO Bank 501 (1.8V) and interfaces to the MPSoC via RGMII for data and MDIO for management. The auxiliary interrupt
(ETH_INTN_PWDNN) and reset (ETH_RSTN) signals also connect to MIO Bank 501.
After power-up the PHY starts with Auto Negotiation enabled, advertising 10/100/1000 link speeds and full duplex. If there is an Ethernetcapable partner connected, the PHY automatically establishes a link with it, even with the MPSoC not configured.
Three status indicator LEDs are on-board near the RJ-45 connector that indicate speed (LD13), valid link state (LD12), and traffic activity
(LD14).
Although the default power-up configuration of the PHY might be enough in most applications, the MDIO bus is available for
management. The PHY is assigned the 5-bit address 01111 on the MDIO bus. With simple register read and write commands, status
information can be read out or configuration changed. The TI PHY follows industry-standard register map for basic configuration.
The RGMII specification calls for the receive (RXC) and transmit clock (TXC) to be delayed relative to the data signals (RXD[0:3], RXCTL
and TXD[0:3], TXCTL). Xilinx PCB guidelines also require this delay to be added. The PHY is configured to insert a delay of 2.0ns between
RXD/CTL and RXC, and a delay of 1.5ns between TXD/CTL and TXC.
6. Reset Sources
6.1 Power-on Reset
6.2 Programmable Logic Reset
6.3 Processor Subsystem Reset
7. Network Connectivity
7.1. Wi-Fi
7.2. 1G Ethernet
https://reference.digilentinc.com/reference/programmable-logic/genesys-zu/reference-manual 21/36